Cardiovascular diseases and Asthma affects between 14 and 15 million people in the United States including 4.8 million children; during the past 15 years, its incidence worldwide has doubled. Asthma is responsible for 100 million person-days of restricted activity and 5000 deaths per year, amounting to $8.1 billion in direct heath related costs; there is uncertainty about the specific factors that are contributing to its rise. Cardiovascular disease and chronic obstructive pulmonary disease are also suspected to be related to environmental exposures but, as with asthma, there is uncertainty about the importance of specific causative agents. There is an ongoing need to conduct studies that investigate the impact of environmental and occupational particulate contaminants on the health of the population. Unfortunately, the utility of such studies has been hampered by the limited capabilities of exposure monitoring equipment currently available to conduct such studies. Miniaturized exposure monitoring devices capable of in-situ analysis of samples would greatly help us understand the relationships between aerosol exposure and health. This proposal addresses the need for better personal exposure assessment, quantification and characterization of ultrafine particles in the environment. A successful outcome will result in an analysis tool that will collect airborne nanoparticles for subsequent in-situ analysis using a microfluidic assay. The toxic potential of inhaled particles is dependent on particle size and chemical composition. Within the respiratory tract, particle size determines the region of deposition, residence time, solubility and tissue uptake; the particle's chemistry determines the potential for biochemical reaction with tissue and cells. There is a growing awareness that exposure scenarios are extremely complex, consisting of time varying concentrations and chemistries within all size classes. Exposure to complex environmental agents, such as ultrafine particulate matter derived from diesel exhaust, or engineered nanomaterials in the households and occupational setting and the effect on the health outcome need to be examined. We anticipate that this novel cost effective approach allows us to apply this technology to many established and emerging areas of health research, as well as position this technology for rapid growth in several markets from consumer product to environmental monitoring (pharmaceutical and semiconductor industries, HVAC, and regulatory monitoring) and surveillance networks (military and security markets). Thus, we will aggressively market our product both domestically and internationally.